The present invention is directed to a radial seal arrangement. In particular, the present invention is directed to an improved radial seal arrangement for creating a seal with the surface of a moveable member.
Radial seal arrangements may be used in a variety of applications to create a seal with a moveable member. In one such application, a radial seal arrangement is used to prevent lubricating fluid from leaking from a housing that supports a moving shaft. In this type of application, the housing usually includes a counter bore that receives the radial seal arrangement and positions the radial seal arrangement at or near the exit point of the shaft from the housing.
A radial seal arrangement typically includes a rigid support member and a sealing element. When the radial seal arrangement is inserted into the counter bore in the housing, the rigid support member engages the surface of the counter bore to hold the radial seal arrangement in the housing. The support member also supports the sealing element to ensure that the sealing element engages the surface of the shaft.
A typical sealing element in a radial seal arrangement includes at least one lip that engages the surface of the shaft as the shaft moves within the housing. In some types of radial seal arrangements, such as shown in U.S. Pat. No. 6,045,137, a radial seal arrangement includes two lips that engage the surface of the shaft. The outer lip creates a dirt seal that prevents dirt, or other debris, from entering the housing, while the inner lip creates a fluid seal that prevents fluid from leaking out of the housing.
Because the lips of the radial seal arrangement must remain in contact with the surface of the shaft to maintain the seal, the radial seal arrangement is configured to have a close fit with the surface of the shaft so that the lips exert a relatively high pressure on the surface of the shaft. After extended use, the pressure of the lips on the surface of the shaft may create wear marks, such as grooves, in the surface of shaft. Excessive wear marks on the shaft may reduce the effectiveness of the radial seal arrangement and allow fluid to leak from the housing.
The rigid support member of the radial seal arrangement is typically press fit into the counter bore of the housing. During installation, the radial seal arrangement is often forced into the counter bore with a blunt instrument, such as a hammer. Striking the metal support with the blunt instrument may cause the metal support to bend or otherwise deform. This deformation may result in the creation of a gap between the metal support and the surface of the counter bore. Thus, even though the radial seal arrangement creates a tight seal with the surface of the shaft, fluid may still leak from the housing though the gap created by the deformation of the metal support during installation of the radial seal arrangement.
The radial seal arrangement of the present invention solves one or more of the problems set forth above.
To attain the advantages and in accordance with the purposes of the invention, as embodied and broadly described herein, the invention is directed to a radial seal arrangement for sealingly engaging an outer surface of a shaft. The radial seal arrangement includes a support member that has a first leg with an outer surface and that extends substantially perpendicular to a reference axis. A second leg of the support member extends substantially parallel to the reference axis from the first leg to a first end. The radial seal arrangement also includes a body portion. The body portion includes an outer peripheral surface that extends substantially parallel to the reference axis from the first leg to a point past the first end of the second leg and a first radial face that extends substantially coplanar to the outer surface of the first leg. The first radial face includes a relief notch. The body portion further includes a first sealing portion that has a first chamfered surface extending from the first radial face to a first lip and a second sealing portion that is separated from the first sealing portion by a first recessed area and is separated from the outer peripheral surface by a second recessed area. The second sealing portion includes an edge that extends substantially perpendicular to the reference axis and a second chamfered surface that extends from the edge to a second lip. The first lip and the second lip are spaced from each other along a line generally parallel to the reference axis.
In another embodiment, the present invention is directed to a sealing assembly that includes a shaft having an outer surface and a housing that has an opening configured to receive the shaft and a counter bore. The sealing assembly also includes a radial seal arrangement that is insertable into the counter bore of the housing. The radial seal arrangement includes a support member with a first leg that has an outer surface and that extends substantially perpendicular to a reference axis. A second leg of the support member extends substantially parallel to the reference axis from the first leg to a first end. The radial seal arrangement also includes a body portion having an outer peripheral surface that extends substantially parallel to the reference axis from the first leg to a point past the first end of the second leg and is configured to contact a surface of the counter bore. The body portion also has a first radial face that extends substantially coplanar to the outer surface of the first leg. The first radial face includes a relief notch. The body portion further includes a first sealing portion that has a first chamfered surface that extends from the first radial face to a first lip and a second sealing portion that is separated from the first sealing portion by a first recessed area and is separated from the outer peripheral surface by a second recessed area. The second sealing portion includes an edge that extends substantially perpendicular to the reference axis and a second chamfered surface that extends from the edge to a second lip. The first lip and second lip are configured to engage the surface of the shaft.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.